I've got a bowl-lift Pro 450 that I can't say a single bad thing about.
I bought my mom a tilt-head one, and when you're kneading bread dough, the latch that keeps the head in place walks and the head pops up. Customer support's verdict? "That's normal"
Absolutely the truth about the tilt-neck version. The pin should really have an E-clip and cotter pin to keep it secure. Someone here posted a thing about retrofitting the mixer to solve this very problem once, but I cannot recall who it was.